ios – 如何对两个动画进行排序,延迟时间间隔

我有一个UI ImageView,我想旋转180度,占用1秒,然后我想在这个位置等待1秒,然后旋转180度回到原来的位置需要1秒钟.

我该如何做到这一点？我已经尝试了100种方法,它不断向后弹回而不是向后旋转

编辑：我忘了添加我需要这个无限重复

您可以在UIView.animate上显示的completionHandler中执行第二个动画

let duration = self.transitionDuration(using: transitionContext)

let firstAnimDuration = 0.5
UIView.animate(withDuration: firstAnimDuration, animations: {
    /* Do here the first animation */
}) { (completed) in

   let secondAnimDuration = 0.5
   UIView.animate(withDuration: secondAnimDuration, animations: { 
       /* Do here the second animation */
   })
}

现在你可能有另一个问题.

如果使用CGAffineTransform旋转视图,并且为每个动画分配一个此类型的新对象到view.transform,您将丢失先前的变换操作

所以,根据这篇文章：How to apply multiple transforms in Swift,你需要连接转换操作

2动画块的示例

这是一个旋转180并在1秒后返回原点的例子：

let view = UIView.init(frame: CGRect.init(origin: self.view.center, size: CGSize.init(width: 100, height: 100)))
view.backgroundColor = UIColor.red
self.view.addSubview(view)

var transform = view.transform
transform = transform.rotated(by: 180)

UIView.animate(withDuration: 2, animations: {
    view.transform = transform
}) { (completed) in

    transform = CGAffineTransform.identity
    UIView.animate(withDuration: 2, delay: 1, options: [], animations: { 
        view.transform = transform
    }, completion: nil)
}

.repeat动画和.autoreverse的示例

.animate方法使您能够设置一些动画选项.特别是结构UIViewAnimationOptions包含：

> .repeat,无限重复你的动画块
> .autoreverse,将您的视图恢复到原始状态

考虑到这一点,你可以这样做：

var transform = view.transform.rotated(by: 180)
UIView.animate(withDuration: 2, delay: 0, options: [.repeat, .autoreverse], animations: {
     self.myView.transform = transform
})

但是你需要在两个动画之间有一个延迟,所以你需要这样做：

递归动画示例和1秒的延迟

只需在ViewController中创建一个方法,为视图设置动画.在最后一个completionHandler中,只需调用该方法来创建一个无限循环.

最后,您需要在viewDidAppear上调用该方法来启动动画.

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    self.animation()
}


func animation() {
    var transform = view.transform
    transform = transform.rotated(by: 180)

    UIView.animate(withDuration: 2, delay: 0, options: [], animations: {

        self.myView.transform = transform

    }) { bool in
        transform = CGAffineTransform.identity

        UIView.animate(withDuration: 2, delay: 1, options: [], animations: {

            self.myView.transform = transform

        }, completion: { bool in
            self.animation()
        })
    }
}